Fungal endophyte symbiosis and plant diversity in successional fields.
The hypothesis that fungal endophyte symbiosis reduces diversity in successional fields was tested by manipulating infection of tall fescue (Festuca arundinacea cv. KY-31) in plots established at the Indiana University Botany Experimental Field. The test area, which consisted of perennial grasses and forbs, was ploughed and disced and alternating plots were then sown with tall fescue seed uninoculated or inoculated with Neotyphodium coenophialum. Over a 4-year period (1994-98) species richness declined and tall fescue dominance increased in infected plots relative to uninfected plots without differences in total productivity. It is concluded that the host-specific endophyte can alter plant community structure and may be reducing plant diversity throughout its expanding range.